1. Field of the Invention
The present invention relates to a connector for electrical connection to a counterpart flat contact, and more particularly to a connector including a contact member capable of removing an oxide layer by contacting with the counterpart flat contact under pressure.
2. Description of the Related Art
In an electrical connector, sometimes an oxide layer or other insulating layer is formed over time on the surface of a terminal and/or the surface of a counterpart flat conductor terminal (i.e., a counterpart circuit part), or sometimes dust is deposited on the terminal and/or the counterpart circuit part. The presence of an insulating layer or dust may cause trouble in an electrical connection. To avoid such trouble, an electric connector capable of performing a so-called “wiping” action has been known, in which an insulating layer or dust can be removed by a mutually sliding motion of terminals contacting with each other under a contact pressure during a connecting operation with respect to a counterpart electrical connector or flat conductor.
Japanese Unexamined Patent Publication (Kokai) No. 2008-276987 (JP2008-276987A) describes an electrical connector including a contact member adapted to contact a counterpart contact having a flat plate shape. As depicted in FIGS. 10A-10C, the electrical connector of JP2008-276987A includes a contact member 1 capable of enlarging an effective wiping distance. The contact member 1 is formed by a thin conductive plate, and is assembled into a housing (not shown) which in-turn accommodates a large number of contact members. The contact member 1 is supported on the housing so that a contact part 5 at the end of the contact member 1 can project outward from and be retracted in a slit formed in a top surface of a protective cover (not shown) attached to the housing.
The contact 1 includes a first spring part 3 extending upward from a base part 2, a second spring part 4 extending generally parallel to the first spring part 3, and a contact part 5 formed at the end of the second spring part 4. The second spring part 4 is formed to be able to bend more easily than the first spring part 3.
Due to the above structure, the contact member 1 acts so that, when a flat plate-shaped counterpart contact C pushes the contact part 5 downward, the contact part 5 moves in a direction α (FIG. 10A) due to the deformation of the first spring part 3 and also moves in a direction β (FIG. 10B), opposite to the direction α, due to the deformation of the second spring part 4. Therefore, when the contact member 1 contacts the flat plate-shaped counterpart contact C, the contact part 5 moves back and forth with respect to the counterpart contact C, whereby a relatively long effective wiping distance can be ensured.
Japanese Unexamined Patent Publication (Kokai) No. 2010-219014 (JP2010-219014A) describes an electrical connector in which a wiping amount and a wiping start position are previously determined so as to enable good electrical connection with a counterpart connector. As depicted in FIGS. 11A and 11B, the electrical connector of JP2010-219014A includes a contact member 10 formed from a material having superior electrical conductivity, which is provided with a contact part 10A adapted to be pushed against and electrically connected to an external terminal, a spring part 10D applying a contact pressure to the contact part 10A, and an attachment/fastening part extending from the spring part 10D and adapted to be attached to a connector housing 11. The spring part 10D of the contact member 10 is provided with a plurality of U-shaped spring elements connected in series with each other to form a meandering (or successive S-shape) profile, each U-shaped spring element including a pair of parallel arms 10d1 arranged side-by-side with a predetermined space defined therebetween and a curved part 10d2 connecting corresponding ends of the parallel arms 10d1 to each other, and thereby ensuring a sufficient contact pressure for the contact part 10A.
The contact member 10 also includes, between the contact part 10A and the spring part 10D, a wiping formation part 10B for determining a wiping amount and a wiping start position, which acts to make the contact part 10A move a predetermined distance in a tangential direction of the contact part 10A to slide on a counterpart contact C of an external terminal and thereby perform a predetermined amount of wiping, due to a sliding contact of the wiping formation part 10B with a side wall 12f of a contact member receptacle 12 of the connector housing 11, during a time when the contact part 10A is pushed by the external terminal.
In the electrical connector described in JP2008-276987A, the first spring part 3 and the second spring part 4 of the contact member 1 are spaced from each other in a direction substantially perpendicular to a direction of final contact pressure applied from the flat plate-shaped counterpart contact C, so that strength of the spring parts may become insufficient to maintain a contact pressure for ensuring a predetermined electrical connection.
On the other hand, in the electrical connector described in JP2010-219014A, the contact member 10 is provided with a spring part formed from a plurality of U-shaped springs connected in series with each other to form a meandering (or continuous S-shape) profile, so that a sufficient contact pressure can be applied to the contact part 10A from the flat plate-shaped counterpart contact C. However, in the contact member 10, the spring part only performs a spring operation (i.e., an elongate and contract operation), and a wiping operation of the contact part in a direction perpendicular to the direction of the spring operation cannot be obtained by itself. Therefore, it is necessary to provide the wiping formation part 10B for obtaining the wiping operation. The wiping formation part 10B acts to contact the side wall 12f formed adjacent to the opening of the contact member receptacle 12 to protrude toward the center of the opening, and thereby enable the contact part to operate a wiping operation.